JP2879288B2 - Caliper body of vehicle disc brake - Google Patents

Abstract

PURPOSE:To improve the fitting property of parts to a cylinder bore, and to downsize and lighten a caliper body by previously unitizing parts to be inserted to a cylinder bore. CONSTITUTION:A spring guide 26 is provided with an outer claw 26a, an inner claw 26b and a spring receiver part 26c. The outer claw 26a is inclined outside in the spring receiver part 26c direction, and the inner claw 26b is inclined inside in the spring receiver part 26c direction. A large diameter cylindrical part 12a of a sleeve piston 12 is formed with an outer groove 12c. A circumferential inner groove 28 is formed at a position of a cylinder hole 8 outside of the large diameter cylinder part 12a. The inner claw 26b is fitted in the outer groove 12c, and the spring guide 26 is fitted to the sleeve piston 12, and among the parts to be inserted to the cylinder hole 8, at least the sleeve piston 12, an adjust bolt 22, a bearing 24, a bearing receiver 25 and an adjust spring 17 are unitized previously, or nearly the whole, which includes an adjust nut 14 and a piston 11 besides the described parts, is unitized previously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc brake used for a traveling vehicle such as a four-wheeled vehicle, and more particularly, to a caliper body in which parts to be inserted into a cylinder hole are unitized in advance to improve the assemblability. Related to the structure.

[0002]

2. Description of the Related Art Disc brakes used in four-wheeled vehicles and the like are disclosed, for example, in Japanese Utility Model Laid-Open Publication No. 61-58744. This disc brake is equipped with a hydraulic brake operated by a brake pedal and a mechanical brake operated by a hand lever or a foot pedal. The parking brake has a piston and cylinder on the cylinder hole opening side. An adjuster combining an adjust bolt and an adjust nut is arranged between the sleeve piston on the bottom side of the hole.

[0003] The adjusting nut is disposed inside the piston, and is engaged with the adjusting bolt by a multi-thread screw. Also, a clutch plate integrally formed with the adjustment bolt,
Between the spring guide engaged with the cylinder hole,
The adjusting spring is contracted, the adjusting bolt is urged toward the bottom of the cylinder hole by the elastic force of the adjusting spring, and the clutch plate is engaged with the clutch hole of the sleeve piston.

In the above-mentioned adjuster, when the lining of the friction pad is worn by a predetermined amount or more, the clutch fitting between the clutch plate and the clutch hole is disconnected, and the adjustment bolt is screwed out toward the bottom of the cylinder hole to adjust the adjustment nut. Is automatically changed so that the braking gap between the disk rotor and the friction pad is kept constant.

[0005]

In such a configuration, from the assembly of the sleeve piston to the circlip for engaging the spring guide with the cylinder hole,
Although it is the smallest unit of assembly, since an adjust bolt, a bearing, a bearing receiver, an adjust spring, and a spring guide are provided between the sleeve piston and the circlip, these must be assembled one by one in the cylinder hole. In addition, when the sleeve piston is assembled and the circlip is fitted, a large amount of time and labor must be performed for a lot of internal parts, which is a complicated operation.

The present invention has been made in view of such circumstances, and an object of the present invention is to improve the assemblability by unitizing parts inserted into a cylinder hole, and to improve the assemblability. An object of the present invention is to reduce the size and weight of a caliper body.

[0007]

In order to achieve the above object, according to a first aspect of the present invention, a piston is accommodated at a tip opening side of a cylinder hole, and a sleeve piston is accommodated at a bottom side of the cylinder hole. An adjuster in which an adjust nut and an adjust bolt are screwed is disposed between the adjuster and the piston, the adjust nut is fitted to the piston, and a clutch plate provided on the adjust bolt and the cylinder hole are engaged. An adjusting spring is contracted between the adjusting spring and a spring guide to be attached, and the adjusting bolt is urged toward the bottom of the cylinder hole by the elastic force of the adjusting spring, so that the clutch plate of the adjusting bolt is moved to the sleeve piston. The caliper body of a disc brake for a vehicle, which is engaged with a clutch hole of An outer groove is formed in the ston, an inner groove is formed between the inner end surface of the piston and the bottom wall of the cylinder hole, and a spring receiving portion protruding from the sleeve piston toward the opening of the cylinder hole in the spring guide. The spring receiving portion supports one end of the adjusting spring, and the spring guide has an outer claw that is inclined outward toward the spring receiving portion, and an outer claw that is also inclined inward toward the spring receiving portion. An inner claw that fits into the outer groove of the sleeve piston, and a spring guide is assembled to the sleeve piston, and a maximum movement of the sleeve piston is provided between the inner claw and the outer groove. Is set, the outer pawl is fitted into the inner groove of the cylinder hole, and the sleep piston is engaged with the cylinder hole.

In the second invention, the inner groove of the cylinder hole is formed at an outer position of the sleeve piston.

[0009]

The spring guide is mounted on the sleeve piston by fitting the inner claw and the outer groove, and the whole of the inserted parts from the sleeve piston to at least the adjustment bolt or the piston is unitized in advance. These insertion parts are assembled in a predetermined position of the cylinder hole in this unit state.

The outer claw of the spring guide has an outwardly opening slope toward the spring receiving portion. Therefore, when inserting the insertion part unit into the cylinder hole, it is bent inward to allow this. When the component unit reaches the predetermined assembly position inside the cylinder hole, the outer claw expands outward and fits into the inner groove of the cylinder hole, and moves in the direction of the opening of the cylinder hole in which the inserted component unit comes out. Regulate.

According to the second aspect of the present invention, in which the inner groove of the cylinder hole is formed at a position outside the sleeve piston, the space between the piston and the sleeve piston can be reduced to shorten the cylinder body length.

[0012]

An embodiment of the present invention will be described below with reference to the drawings.

The disc brake 1 includes a caliper body 2
The hydraulic actuation mechanism 3 operated by the brake pedal
A caliper body 2 is provided with a parking brake provided with a mechanical operating mechanism 4 for a parking brake operated by a hand lever or a foot pedal.
Are supported movably in the disk axial direction via a pair of sliding pins (not shown).

The caliper body 2 has an operating portion 2a and a reaction portion 2b which are disposed on opposite sides of the disk rotor 5.
And a bridge portion 2c connecting the two over the outside of the disk rotor 5. A pair of friction pads 7, 7 sandwich the disk rotor 5 between the action portion 2a and the reaction portion 2b. It is arranged in. In the action part 2a,
A large-diameter cylinder hole 8 opening to the disk rotor 5 side;
A bearing hole 9 in a direction orthogonal to the cylinder axis and a small diameter connecting hole 10 connecting the cylinder hole 8 and the bearing hole 9 are formed.

A cylindrical piston 11 with a bottom is accommodated at the tip opening side of the cylinder hole 8, and a stepped sleeve piston 12 is accommodated at the bottom side of the cylinder hole 8. An adjuster 13 is disposed between the pistons 11 and 12 so that the braking gap between the disk rotor 5 and the friction pad 7 can be constantly maintained at a constant interval by the adjuster 13.

The piston 11 is accommodated in the cylinder hole 8 with the bottom wall 11a facing the disk rotor, and an adjust nut 14 of an adjuster 13 is disposed on the inner central axis of the piston 11. Adjust nut 1
Reference numeral 4 denotes a coil spring 1 which is restricted in rotation by engaging a flange 14a of a head portion with a bottom wall 11a, and is contracted between a spring receiver 16 locked by a circlip 15.
7, the piston 11 is urged toward the bottom wall 11 a of the piston 11. Between the cylinder hole 8 and the piston 11,
A hydraulic chamber 18 is defined, and the above-mentioned hydraulic operating mechanism 3 includes the piston 11 and the hydraulic chamber 18 and the hydraulic chamber 18 in the action section 2a.
And a union hole 19 drilled toward.

The sleeve piston 12 has a large-diameter cylindrical portion 12a provided in the hydraulic chamber 18 and an O-ring 2
0, a small-diameter cylindrical portion 12b housed in a liquid-tight manner through the large-diameter cylindrical portion 12a and the bottom wall 2d of the cylinder hole 8.
The rotation in the circumferential direction is restricted by the detent pin 21 spanned between. The detent pin 21 is fixed to the sleeve piston 12 before being inserted into the cylinder hole 8 by press fitting or screwing in advance. Large diameter cylindrical part 12a
Are formed with three outer grooves 12c on the outer peripheral surface thereof. A large-diameter clutch hole 12d that opens in the direction of the opening of the cylinder hole 8 is fitted inside the large-diameter cylindrical portion 12a. A mating hole 12e is formed, and a conical engagement recess 12f is formed on the rear end surface of the small-diameter cylindrical portion 12b.

The adjuster 13 includes an adjust nut 14 and an adjust bolt 22 screwed to the nut 14.
It consists of The adjusting bolt 22 is integrally formed with a male screw 22a that is threadedly engaged with the adjusting nut 14, a rear shaft 22b protruding from the adjusting nut 14 toward the bottom of the cylinder hole 8, and an intermediate portion of the rear shaft 22b. It has a large-diameter clutch plate 22c. The rear end of the rear shaft 22b is fitted in the fitting hole 12 of the sleeve piston 12.
e through the seal member 23, and the clutch plate 22c
Is engaged with the inner peripheral taper surface of the clutch hole 12d.

The rear shaft 22 is provided outside the clutch plate 22c.
A bearing 24 and a bearing receiver 25 fitted in the b are supported, and a cylindrical spring guide 26 is mounted on the sleeve piston 12. In the spring guide 26, three outer claws 26a and three inner claws 26b are alternately formed at equal intervals on a cylindrical portion at one end which is a side to be attached to the sleeve piston 12, and a cylinder is formed at the other end. A spring receiving portion 26 that protrudes toward the opening of the hole 8 and wraps the outside of the clutch plate 22c and the rear shaft 22b in a stepped manner.
c.

The outer claw 26a raises the notch tongue formed in the cylindrical portion on the mounting side outward, inclines so as to expand in the direction of the spring receiving portion 26c, and the inner claw 26b
Similarly, the cut tongue piece is pushed inward and inclined so as to be narrowed in the direction of the spring receiving portion 26c. The tip of the outer claw 26a slightly spreads outward from the diameter of the cylinder hole 8, and The tip of the claw 26b has a shape that is slightly inside the outer groove 12c of the sleeve piston 12.

The spring guide 26 fits the inner claw 26b into the outer groove 12c while covering the mounting-side cylindrical portion on the large-diameter cylindrical portion 12a of the sleeve piston 12.
It is attached to the sleeve piston 12 with one touch. Since the inner claw 26b is inclined inward toward the spring receiving portion 26c, when an external force is applied to the spring guide 26 in the pulling-out direction, the tip of the inner claw 26b abuts on the side wall of the cylinder groove opening of the outer groove 12c. Regulate this. The bottom of the large-diameter cylindrical portion 12a is slightly larger in diameter than the opening of the cylinder hole.
When an external force is applied to the bottom of the inner claw 26b, the end of the inner claw 26b on the bottom side of the cylinder hole (in this embodiment, the same as the end surface of the cylindrical portion on the mounting side of the spring guide 26) abuts on the bottom wall of the outer groove 12c. Regulate this.

One end of an adjusting spring 27 is supported by the spring receiving portion 26c. The adjusting spring 27, which is contracted between the spring receiving portion 26c and the bearing receiving portion 25, adjusts the adjusting bolt 22 to the cylinder hole 8. It is urged toward the bottom to hold the clutch plate 22c and the clutch hole 12d in the engaged state.

Further, the above-described spring receiving portion 26c allows at least the internal components up to the sleeve piston 12, the adjusting bolt 22, the bearing 24, the bearing receiving 25, and the adjusting spring 27 to be assembled into the cylinder hole 8 in the smallest unit. As a unit in advance. Furthermore, by screwing the adjusting nut 14 to the adjusting bolt 22, most of the inserted components up to the piston 11 can be integrated.

An inner groove 28 is provided in the cylinder hole 8 at a position outside the large-diameter cylindrical portion 12a.
The outer claw 26a of the spring guide 26 incorporated into the predetermined position of the cylinder hole 8 is fitted. As described above, the outer claw 26a is inclined outward in the direction of the spring receiving portion 26c, and the outer end is further expanded slightly outside the diameter of the cylinder hole 8; To allow the spring guide 26 to be inserted.
When the spring guide 26 reaches a predetermined mounting position in the cylinder hole 8, the outer claw 26 a expands outward and fits into the inner groove 28, so that the spring guide 26 does not come off in the direction of the opening of the cylinder hole 8. To be regulated.

In the above-described assembling position, the end of the inner claw 26b on the bottom side of the cylinder hole (in this embodiment, the spring guide 26
A clearance C larger than the maximum stroke of the sleeve piston 12 is set between the outer wall 12c and the end wall on the bottom side of the cylinder hole of the outer groove 12c. The spring guide 26 is prevented from interfering with the sleeve piston 12 even when the operation mechanism 4 is moved to the maximum in the direction of the opening of the cylinder hole 8.

A camshaft 29 is provided in the bearing hole 9.
A push rod 31 is suspended between a cam groove 29 a of the cam shaft 29 and an engagement recess 12 f of the sleeve piston 12. A cam lever 32 is fixed to the protruding shaft portion 29b of the camshaft 29 by a fixing nut 33, and a coil-shaped return spring 34 is wound around the outer periphery of the fixing nut 33. The camshaft 29 and the cam lever 32 The torsion force of the return spring 34 constantly urges the non-operating direction.

A brake wire (not shown) connected to a hand lever or a foot pedal in the driver's seat is connected to an outer end of the cam lever 32. The cam lever 32 pulled by the brake wire causes the cam shaft 29, the push rod and the like. The mechanical operation mechanism 4 described above includes the part 31, the sleeve piston 12, the adjustment bolt 22, and the adjustment nut 14.

In a normal brake operation using the hydraulic operating mechanism 3, the hydraulic fluid pressurized to the hydraulic master cylinder by depressing the brake pedal is introduced into the hydraulic chamber 18 through the union hole 19, and the piston 11 is moved. By pushing in the direction of the disk rotor, one friction pad 7 is pressed against one side surface of the disk rotor 5. Next, the caliper body 2 moves in the direction of the action portion 2a by this reaction force,
The reaction force claw 2e b presses the other friction pad 7 against the other side surface of the disk rotor 5, and a braking action is performed.

In the parking brake operation by the mechanical operation mechanism 4, the brake wire is pulled by the hand lever or the foot pedal, and the cam lever 32 and the cam shaft 29 rotate integrally in the operation direction, and the push rod 31 is moved. Move toward disk rotor. The thrust converted to the push rod 31 is applied to the sleeve piston 1
2, the adjustment bolt 22 and the adjustment nut 14 are transmitted to the piston 11 to push the piston 11 in the direction of the disk rotor to press the friction pads 7, 7 against the disk rotor 5 in the same manner as in the hydraulic operation. Thus, a braking action is performed.

Since the spring guide 26 is engaged with the cylinder hole 8 by fitting the outer claw 26a and the inner groove 28, the adjusting spring 27 is moved by the advance of the sleeve piston 12 in the above-described parking brake operation.
Are being compressed. Since the clearance C is set between the inner claw 26b and the outer groove 12c, the spring guide 26 does not interfere with the sleeve piston 12 even when the sleeve piston 12 advances to the maximum.

When the braking gap between the disk rotor 5 and the friction pad 7 is within a predetermined range, the adjuster 13 does not perform the adjusting operation, only the piston 11 moves the backlash of the adjusting nut 14 and the adjusting bolt 22.

If the above-mentioned braking gap becomes larger than the backlash by repeated braking, the piston 11 and the adjusting nut 14 are connected to the adjusting bolt 22 and the adjusting nut 14 during braking by the hydraulic operating mechanism 3. While filling the backlash between them, the disk drive advances greatly toward the disk rotor, and further moves the adjustment bolt 22 in the direction of the disk rotor. Thereby, the clutch plate 22c separates from the clutch hole 12d against the elastic force of the adjusting spring 27, and the clutch engagement is released.

The adjusting bolt 22 disengaged from the clutch hole 12d is engaged with the adjusting spring 2d.
With the resilience of 7, the cylinder plate 8 is extended toward the bottom of the cylinder hole 8, and the clutch plate 22c is again engaged with the clutch hole 12d and stopped. As a result, the retracted positions of the piston 11 and the adjustment nut 14 whose braking has been released are changed to the disk rotor 5 side, and the disk rotor 5
A predetermined braking gap is automatically set between the friction pad 7 and the friction pad 7.

In this embodiment, the spring guide 26 is mounted on the sleeve piston 12 with one touch by fitting the inner claw 26b and the outer groove 12c.
6c, the sleeve piston 12 and the adjustment bolt 22,
The bearing 24, the bearing receiver 25, the adjustment spring 27, or the entire part up to the piston 11 is unitized in advance as an assembly unit. The unitized insertion part is inserted into the cylinder hole 8 as it is, and when it reaches a predetermined installation position, the outer claw 26a of the spring guide 26 expands and the inner groove 2 of the cylinder hole 8 is opened.
8 and the spring guide 26 is engaged with the cylinder hole 8.

As described above, according to the present embodiment, most of the insertion parts or most of the insertion parts to be assembled to the cylinder hole 8 are unitized in advance, and then are integrally assembled to the cylinder hole 8. Compared with the conventional method in which the insertion parts are assembled one by one with a dedicated jig, the number of working steps can be greatly reduced. Further, since the inner groove 28 of the cylinder hole 8 is formed in a circumferential shape, there is no directionality in insertion of the inserted part, and the operation is further simplified. Moreover, despite the fact that the insertion parts can be assembled with one touch, the outer claws 26a of the spring guides 26 fit into the inner grooves 28 of the cylinder holes 8 after the assembly, so that the insertion parts may fall loose. There is no.

Further, the circlip, which has conventionally prevented the spring guide from coming off, can be omitted, and by omitting the locking groove for the circlip, the interval between the piston 11 and the sleeve piston 12 can be reduced, so that the working portion can be reduced. Since the length of 2a can be shortened, the weight balance between the action portion 2a and the reaction portion 2b is improved, and the caliper body 2 can be made compact and lightweight.

In the above-described embodiment, the inner groove of the cylinder hole is formed at the outer peripheral position of the large diameter cylindrical portion of the sleeve piston. However, in the present invention, this inner groove is formed between the inner end of the piston and the bottom wall of the cylinder hole. It may be set between. Further, the number of the inner grooves may be divided into a number corresponding to the outer claws in addition to the circumferential shape in the embodiment.

Further, the sleeve piston of the embodiment is provided with a small-diameter cylindrical portion accommodated in the connecting hole, but the connecting hole and the small-diameter cylindrical portion are omitted so that the sleeve piston can be directly mechanically pushed directly. You may.

[0039]

According to the present invention, the adjusting spring accommodated in the spring receiving portion of the spring guide is provided by fitting the inner claw of the spring guide into the outer groove of the sleeve piston and assembling the spring guide to the sleeve piston. Since most or most of the inserted parts to be assembled to the cylinder hole are unitized beforehand,
The work of assembling the cylinder guide into the cylinder hole can be largely omitted, and the circlip, which has conventionally prevented the spring guide from coming off, can be eliminated. Further, since the inner claws of the spring guide are inclined inward toward the spring receiving portion, the spring guide can be easily attached to the sleeve piston with one touch.

In addition, the spring guide is provided with an outer claw which is inclined to open outward in the direction of the spring receiving portion.
The insertion of the insertion part unit into the cylinder hole can be easily performed with one touch without using a jig, and when the insertion part unit reaches a predetermined mounting position inside the cylinder hole, the outer claw is fitted with the inner groove of the cylinder hole. By fitting, the movement of the cylinder hole in the opening direction of the insertion component unit is reliably restricted.

Further, by forming the inner groove of the cylinder hole at a position outside the sleeve piston, the length between the piston and the sleeve piston can be shortened, so that the weight balance of the caliper body is improved and the size of the entire caliper body is reduced.・ Lightening can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional front view of a disc brake showing one embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 1;

FIG. 4 is a partial cross-sectional front view of an insertion part unit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Disc brake 2 ... Caliper body 3 ... Hydraulic operating mechanism 4 ... Mechanical operating mechanism for parking brake 5 ... Disk rotor 7 ... Friction pad 8 ... Cylinder hole 9 ... Bearing hole 10 ... Cylinder hole 8 and bearing hole 9 11 ... A piston accommodated in the tip opening side of the cylinder hole 8 ... A sleeve piston accommodated in the bottom side of the cylinder hole 8 a ... A large-diameter cylindrical portion of the sleeve piston 12 12b ... A sleeve piston 12 12c ... Outer groove 12d ... Clutch hole 13 ... Adjuster 14 ... Adjust nut 18 ... Hydraulic chamber 19 ... Union hole 22 ... Adjust bolt 22a ... Adjust bolt 22 male screw 22b ... Adjust bolt 22 rear shaft 22c ... Clutch plate of adjust bolt 22 24 Bearing 25 Bearing Reference numeral 26 denotes a cylindrical spring guide mounted on the sleeve piston 12. Reference numeral 26a denotes an outer claw of the spring guide 26b... Inner claw 26c of the spring guide 26. c) a spring receiving portion of the spring guide 26. 27: a bearing receiver 25 and a spring receiving portion 26c. Adjusting spring 28 contracted between the inner grooves formed around the cylinder hole 8

Claims (2)

(57) [Claims] 1. A piston is accommodated in a front end opening side of a cylinder hole and a sleeve piston is accommodated in a bottom side of the cylinder hole, and an adjust nut and an adjust bolt are screwed between the sleeve piston and the piston. The adjust nut is engaged with a piston, and an adjust spring is contracted between a clutch plate provided on the adjust bolt and a spring guide engaged with the cylinder hole. In the caliper body of the disc brake for a vehicle, the elastic bolt of the adjust spring urges the adjust bolt toward the bottom of the cylinder hole to clutch the clutch plate of the adjust bolt to the clutch hole of the sleeve piston. An outer groove is formed in the sleeve piston, and an inner groove is formed on the sleeve piston. One end of the adjusting spring is formed in the spring guide by forming an inner groove between the bottom wall of the cylinder and the spring guide, the spring receiving portion projecting from the sleeve piston toward the opening of the cylinder hole. The spring guide is formed with an outer claw that is inclined outward toward the spring receiving portion and an inner claw that is also inclined inward toward the spring receiving portion, and the inner claw is attached to the sleeve piston. And a spring guide is assembled to the sleeve piston, and a clearance is set between the inner claw and the outer groove to allow the maximum movement of the sleeve piston. A caliper body for a disc brake for a vehicle, wherein a sleep piston is engaged with a cylinder hole by fitting into an inner groove. 2. The caliper body for a vehicle disk brake according to claim 1, wherein an inner groove of said cylinder hole is formed at a position outside said sleeve piston.